Manufacture of 2-aminoanthraquinone



Patented ct. il, i927.

hdiidfidd Wilifitvilltlti imidliilhill idiiiliiiiiil.

DONALTPG. ROGERS, F BUFFALO, NEW YORK, ASSIGNOR TO NATIONAL ANlLl'ilE &CHEMICAL COMPANY, INC., Oi NE'W YORK. N. Y., A CORPORATION OF NEW YORK.

No 'Drawing'.

This invention relates to improvements in the manufacture oiaminoanthraquinones from anthraquinonesulionic acids, and particularlyof --aminoanthraquinone from anthraquinone--sulfonic acid or its salts.

it has been heretofore proposed to malte aminoanthraipiinones bytreating anthraquinonesulfonic acids, or their salts7 with aqueousammonia in the' presence of an oxidizing agent, and it is stated that. ayield of about @lm-Elfi percent ot the Athtanetical can be obtained inthis Way, for example, of 2- amintmnthraquinone `by heating the sodiumsalt of authraquinone-2-sulonic acid with aqueous ammonia andnitrobenzene.

i have found that a greatly increased yield A oi aniinoanthraquinones,amounting in some mises to as much ae: 9() percent or more of thetheoretical. can be obtained by addingr amuumium salts, particularlyammonium chloride, in the treatment oi anthraquintmesub tonic acids ortheir salts with aqueous ainmouia in the presence of oxidizing agents.Thevyields which l have obtained in this way are considerably higherthan those obtained by any method hitherto proposed, in so lliar as I amaware.

The invention will be illustrated by the fob lowing soeciiic examples,but it is understood that the invention is not limited thereto. Theparts are by weight.

E'aramp/e L -To 360 parts of ammonium chloride dissolved in 725() partsof Q25 per cent aqueous ammonia there is added parts of silver salt(anhydrous sodium salt ot' authraquinone-2-sulfonic acid) and 205 partsnitrobenzene in an autoclave and l1eated with agitation to --lt33 C. foriii- 20 hours, or until the reactirm is completo. -At the end of thistime the ein. si.' oi ammonia is allowed to escape from the autoclaveand is recovered. The crude .2-aminoauthraqui- 'none is then filteredoil', washed with water and dried. A yield ot' about. 1023i) to 1060parts of crude 2-aminoanti1raquinone of a purity of ibi-98 percent canthus be obtained, which corresponds to approximately 87-93 percent oithe theoretical yield. lf desired, the crude Qsaminoanthraquinono can bepurified by methods Well known to the art. Also, from the filtrate, anyunchanged nitrobenzendas Well as the aniline produced in the reaction,can be recovered in the usual manner.

It `vill bo noted that the amount of uitro- Serial No. 599,928.

benzene employed is about two-lifteenths of the weight of silver saltused.

Aif in this exmnple, the :205 parts of nitrobenxeue are replaced b vi203 parts o|`y potassium chiot-ate, and the process carried out in asimilar manner, there can be obtained a yield of .2-a'minoauthraquinoneeorresponib ing to about R2 percent. oi' theory as com pared to a yieldof about T5 perc'au when no ammoniumchloride is employed. ln :1 siniilarmanner, i-aminoautln'aquinoue may be prepared from:mthraquinonel-sulfoniracid or its salts.

Eafamp/c {2-#165 parts of the sodium salt ofanthraquinone-1.5-disul`fonic acid. 40u() parts of 2G percent aqueousammonia. im parts of ammonium chloride, .and Tt) parts ot' sodiumehlorate are heated together whilst stirring in an autoclave for 1()hoursA at 18m G. After allowingr the excess anunonia to escape at, theend of the operation` the lf)- iliaminoanthrarpiinone is littered ott.washed with water and dried. The yield is approximately l() percentgreater than when no mnmdnium chloride is used. The improvement in thepercentage yield is even greater when 92 parts oi" nitrobenzcnc is usedin place of the T9 partsI of sodium chlorate in this example. In asimilar manner, 1.8-dianiinoanthraquinone, Qibdiaminoanthraquinone andill-diaminoant'hruquinone may be obtained l' rom the corres iondin rnnthraipiinone disulfonic acids or t ieir sa ts.

The process of the present invention is earried out in an analogousmanner on using other suitable oxidizing agents. lor example1 otheraromatic nitrocompounds may be employed, such as dinitrobcnzene,nitrotoluene, nitronaphtlmlene, etc., or their sulfonic acids; or, forexample, sodium arse nato, sodium ,nitrate7 copper sulfate, etc. It ispreferable, however, to employ oxidants which do not of themselves leaveor produce insoluble residues which contaminate the aminoanthraquinonoimpurities and which are difficult to remove.

1t is understood that the invention is not confined to the particularsgiven in the above examples, as these are merely typical. It has beenfound advantageous. however, to employr approximately the calculatedtheoretical quantity of potassium chlorate or sodium chlorate ornitrobcnzene required -to eliminate the sullites produced in thereaction by their oxidation to sulfates. On

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